Metal-organic materials as efficient additives in polymer electrolytes for quasi-solid-state dye-sensitized solar cells

In this paper, we firstly introduced the metal-organic materials ((CH₂)₂O₂Ni, (CH₂)₃O₂Ni) compared with binary transition-metal oxides (ZnCo₂O₄, MnCo₂O₄) as efficient additives into agarose polymer electrolyte for quasi-solid-state dye-sensitized solar cells (DSSCs). The surface morphology, ion concentration and ionic conductivity of the modified agarose electrolytes are characterized by Field Emission Scanning Electron Microscope (FESEM), Ultraviolet–visible Spectra (UV–Vis) and Electrochemical Impedance Spectra (EIS). Moreover, the photovoltaic and electrochemical performances of the DSSCs based on these electrolytes are investigated. Compared with the DSSC assembled with the reference electrolyte, power conversion efficiency (PCE) of DSSCs based on transition-metal oxides display a preliminary improvement from 2.73% to 3.74% (MnCo₂O₄ modified electrolyte) and 3.97% (ZnCo₂O₄ modified electrolyte), however, which are smaller than those modified by metal-organic materials. The PCE of (CH₂)₃O₂Ni based DSSC shows an optimized value of 4.59%, which is attributed to the smoother surface morphology and enhanced conductivity. In addition, the DSSCs assembled with metal-organic materials modified electrolytes exhibits an enhanced durability. - Highlights: • Metal-organic materials could suppress the crystallinity in agarose matrix. • Improved ionic conductivity and morphologies of modified electrolytes were found. • Enhanced conversion efficiency was attributed to the improved ionic conductivity. • Better stability was achieved by adding (CH₂)₂O₂Ni.